The present invention generally relates to a system for monitoring the state of alertness of a driver.
Studies have shown that lack of driver awareness and alertness can contribute to the number of accidents, particularly for long-distance heavy truck drivers who spend many hours on the road. Lack of alertness may delay a driver's response to a traffic condition by only a fraction of a second. Different methods have been proposed for monitoring the alertness of the driver, including position measuring sensors that track eye movement, steering wheel activation sensors to monitor movement of the steering wheel, heart rate sensors that attempt to determine if a driver is falling asleep, etc. These methods have not yet found wide acceptance in commercial applications either because of cost or reliability. Alternate systems have also been proposed which provide a visual activation of some device at set intervals, and then wait for the driver to activate some switch to indicate awareness. U.S. Pat. No. 5,012,226, describes such a system. The present invention improves upon such a driver awareness system by using voice or sound generation and recognition technology along with other auxiliary sensor inputs to minimize the inconvenience for the driver while maximizing effectiveness.
This invention consists of four main subsystems that provide for monitoring the state of alertness of the driver and control appropriate reaction methods. The first subsystem is the central control unit, which can be integrated with other vehicle electronics such as the air bag crash sensor, and may consist of one or more devices. This first subsystem serves to activate the visual or audible signals supplied to the driver, such as an indicator lamp or speech generation circuit, either randomly or at preset time intervals, and then to evaluate the response of the driver in relation to the condition of any auxiliary sensors. The second subsystem consists of a driver response system, such as a voice recognition means, which decodes spoken words to determine if a correct response from the driver has been given. This subsystem then provides a signal back to the first subsystem indicating driver response. The third subsystem performs a driver notification function dependent on the status of the signal from the second subsystem and its subsequent treatment by the first subsystem. This notification can be visual or audible, for example, an alarm to warn the driver. This third subsystem may also be integrated with a vehicle control means that can reduce engine speed or apply the vehicle brakes should the proper sequence of events be recorded. The fourth subsystem is an auxiliary sensor system which provides information from external sensors to the first subsystem to control or modify the function of other subsystems or the response criteria.
It is an object of this invention to provide an easily implemented, cost effective and highly reliable means to measure driver alertness.
It is a further object of this invention to eliminate annoying manual operations performed by the driver as may be required with prior alertness monitoring systems which could promote their disuse.
It is another object of this invention to use existing electronic control units, indicator lamps, buzzers and other devices already available on many vehicles with minor modifications to provide a measure of driver alertness.
It is another object of this invention to improve the effectiveness of a driver awareness system by using auxiliary sensors that provide additional information to optimize the function of the system.
It is another object of this invention to allow the alertness of the driver to be monitored by remote means.
Many other objects and purposes of the invention will be clear from the following detailed description of the drawings.